Telegraph repeater



Oct. 5,1925 1,555,870

H. NYQUiST TELEGRAPH REPEATER Filed June 27, 1923 I i Y ZTORNE Y til Patented Get. 6, 1925.

STATES tssssrc r OFFICE.

HARRY NYQUIST, 0F ELMHURST, NEW YORK, ASSIGNOR T0 AMERICAN TELEJPHONE AND TELEGRAPH COMPANY, A CQBEORATION OF NEW YORK.

TELEGRAPH REXEATER.

Application filed. June 2' 3, 1923. Serial No. 648,068.

To all whom it may concern.

Be it'known that l, HARRY NY UIs'r, residing at Elmhurst, in the county of Queens and State of New York, have invented certain Improvements in Telegraph Repeaters, of which the following is a specification.

This invention relates to improvements in telegraph circuits and more particularly to repeater arrangements utilized in such circuits.

The telegraph system of this invention is similar to the so-called single line telegraph and half-duplex systems in that it permits operation in either direction but not both simultaneously. The means whereby this is accomplished are, however, different from those employed in former systems. Whereas selectivity as to direction is attained'in the single line telegraph bymeans of holding relays and in the case of halt-duplex lay means of balance, the arrangements of this invention utilize difierences in polarity between the voltages employed for attaining such selectivity. This is accomplished by making the repeaters responsive to voltages of a given polarity and at the same time capable of impressing voltage of the opposite polarity on the line. Where a number of repeaters are employed adjacent repeaters are made to respond to opposite polarities. @ther features and objects of the invention will appear more fully from the detailed description hereinafter given. Y

Elie invention may be more fully understood from the following description together with the accompanying drawing in the Figures 1, 2, and 3 of which the invention is illustrated. Fig. 1 shows a circuit diagram of the telegraph system of the invention in which the repeaters comprise polarized relays. In Fig. 2 the repeater ele ment is shown. as comprising electron tubes. In Fig. 3 is shown a modification of one of the repeaters of Fig. 1 suitable for use on a metallic circuit. Similar reference numerals have been utilized to denote like parts in all of the figures.

In Fig. 1 is sh wn a telegraph line L interconnecting two stations A and B. At station A is shown sending apparatus co1nprising a key K, which controls a relay 1. lhe relay 1 through its armature controls the application of negative current from battery 2 to the line L. For receiving there is connected to the line at station A the sounder apparatus 3. At station ll would be located similar apparatus comprising the key K, which controls relay 10. 'lhc relay 1U through its armature controls the application of positive current to line l. from battery 11. Included in the line are the telegraph repeaters R, and 'R. it will be noted that each repeater consists of two polar rclays, such as relays e and 5 and relays 7 and 8. These relays are slightly biased so as to remain in the position shown when there is no current in the windings.

Consequently, when voltage of a certain polarity is impressed from the line the relay connected to that line will respond. if volt age of the opposite polarity is impressed on the line, however, the relay willnot respond. the magnetizing eliect merely serving to make firmer contact on the contact shown. When the relay operates it will be apparent that battery is connected to the opposite line to that from which the signaling impulse arrived over andthe battery is of the ating will connect battery 6 to the out oing .line section. section potential'of an opposite polarity to This will apply to said line the incomin potential. In this instance battery 6 will apply positive potential to the outgoing line section. The winding of relay 5 is poled similar to that of relay 4 and hence will not respond to this positive potential so that the repeater will not lockup. The positive potential applied to the line from repeater R, will now operate relay 7 in repeater R, as the windin of said relay is poled to respond to potentialof this polarity; The operation of relay 7 will connect battery 9 to the next line section. This battery will apply to said line section potential of a polarity opposite to that of the incoming current. In this instance battery 9 will apply negative potential to the succeeding line section. The winding of relay 8 is poled similar to that of relay 7 and hence will not respond to this negative potential applied to the next line section but will not efiect relay 7. This in turn will operate 10. relay which will' causepositive potential from battery 6 to be applied .to the next line section without effecting relay 4. This in turn Will operate the sounder apparatus 3. Additional repeaters similar to R and R,

might also be connected into the line; It

' will be apparent, however, that the method 'of operation depends on the construction of a repeater such as to impress on theoutgoing line section battery of the opposite polarity from that which it receives so that the .out-

going. impulse will not cause operation of the wrong relay and hence lock the repeater up permanently.

In Fig. 2 is shown an arrangement substantially similar to that of Flg. 1 except that {the repeater element COllSlSlBS." of the vacuum tubedevices 13 and 14 instead of a set of polar relays. The functioning is the I same in this case except that this type of repeater can be made to respond only to posi-' tive impulses, whereas the polar] relay repeaters of Fig. 1 'canbe arrangedto respond to impulses of: either-polarity. Hence it is,

sections interconnected by repeater apparanot possible to have more than a single repeat'erof this type in a circuit. In Fig. 3 is shown an application of the polar relay repeater of the invention to-a metallic circuit.- This arrangement is substantially similar to the arrangements shown 40 in Fig. 1 except that two sets of apparatus are employed, one for each conductor, and the points which are shown grounded here- 'tofore are now shown connected together. In the drawin'gare shown two metallic line sections L and L interconnected by the repeater apparatus which comprises two sets of polar rela s 4', 4", and 5', 5" connected to each con uctor. Relays 4',4"' are arranged and poled so as to respond to our rent of a definite polarity or for purposes of illustration current flow from the upper to the lower conductor. Relays 5', 5" are arranged and poled to res ond to similar current. The operation 0 relays 4', 4" will connect battery 20 to line section L in such a,manner as to transmit currentfiof o posite polarity thereover to o erate t e re ays at the .next repeater, whic are poled and ar I ranged for such current, without interfering with relays 5, 5". I

While the invention has been disclosed in certain specific arrangements which are deemed desirable it isunderstood. thatit isa definite polarity capable of embodiment in many and widely varied forms without de arting from the spirit of the invention as efined in the appended claims.

What is claimed is:

1. A telegraph line comprising two line sections interconnected by repeater apparatus, said repeater apparatus comprising means responsive 'to current of a definite polarity coming in over one line section,

and means controlled thereby for applying current of a different polarity to said other line section.

2. A telegraph line comprising two line sections interconnected by repeater apparatus, said repeater apparatus comprising means associated with each linesection responsive to current of a definite polarity coming in over either line section, and means controlled thereby for applying current of a different polarity to the line section other than the one over which the incoming current. arrives.

3. A telegraph line comprising a plurality of repeaters, each of said repeaters comprising means responsive to incoming current of and means controlled thereby for transmltting outgoing current of a difi'erent polarity over said line, said 'responsive means in alternate repeaters being arranged to respond to currents of different polarities. I i

4. A telegraph line comprising two line tus, said repeater apparatus comprising-a plurality of polar relays connected to each line section and adapted to respond to current of a definite polarity coming in over said line sections, a source of current of a difi'erent polarity from said incoming current, and means controlled by said relays for applying currentfrom said source to either of said line sections.

5. A tele raph line, means to apply current of a definite polarity to said line, a repeater associated with said line, polar relays in said repeater responsive to. said current of definite polarity, means controlled by said relays in said repeater for applying current to said line of a different polarity from'said first mentioned current, a second repeater associated with said line, polar relays in said second re eater responsive to sald second'mentione ,current, and means controlled by'said relays in said second repeater for applying current to said line of a polarity like said first mentioned current.

In testimony whereof, I'have signed my name to this specification this 26th day of June, 1923.

- A v HARRY N omsT; 

